اله  
Saudi Standards, Metrology and Quality Org. (SASO)  
 
 
 
 
 
  
 
 
Draft Standard DS 
 
  
 
SASO/DS/31834/2020  
  
  
 
School buses - body joint strength 
 
 
 
 
 
ICS: 43.080.20 
 
This document is a draft Saudi Standard circulated for comments. It is, therefore, 
subject to alteration and modification and may not be referred to as a Saudi 
Standard until approved by SASO . 
FOR STUDYSASO STANDARD                                                           SASO/DS 31834/2020 
1 
   
Contents 
 
1- Scope ...................................................................................................................................... 2 
2- Complementary references  ................................................................................................. 2 
3- Terms and definitions  .......................................................................................................... 2 
4- Technical requirements  ....................................................................................................... 3 
6- Test procedures  .................................................................................................................... 3 
  
Bibliography  ............................................................................................................................. 5 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
FOR STUDYSASO STANDARD                                                           SASO/DS 31834/2020 
2 
  School buses - body joint strength 
 
1- Scope  
This standard specifies the technical requirements and test procedures for the strength of the 
body panel joints in school bus bodies. 
 
2- Complementary References 
2.1 ASTM E8/E8M "Standard Test Methods for Tension Testing of Metallic Materials". 
 
3- Terms and definitions  
For the purposes of this standard, the following terms and definitions are applied: 
3.1 School bus 
A specially constructed vehicle that is designed to carry more than ten persons to and from 
school, university or related events.  
3.2 Body component 
A part of a bus body made from a single piece of homogeneous material or from a single piece 
of composite material such as plywood.  
3.3 Body panel 
A body component used on the exterior or interior surface to enclose the bus' occupant space.  
3.4 Body panel joint 
The area of contact or close proximity between the edges of a body panel and another body 
component, including but not limited to floor panels, and body panels made of composite 
materials such as plastic or plywood, excluding trim and decorative parts which do not 
contribute to the strength of the bus body, members such as rub rails which are entirely outside 
of body panels, ventilation panels, components provided for functional purposes, and engine 
access covers.  
3.5 Bus body 
That portion of a bus that encloses the bus occupant space, including the floor, but excluding 
the bumpers and chassis frame and any structure forward of the passenger compartment.  
3.6 Maintenance access panel 
A body panel which must be moved or removed to provide access to one or more serviceable 
component(s).  
3.7 Passenger compartment 
Space within the school bus interior that is between a vertical transverse plane located 762 mm 
in front of the forwardmost passenger seating reference point and including a vertical transverse 
plane tangent to the rear interior wall of the bus at the vehicle centerline.  
3.8 Serviceable component 
Any part of the bus, of either a mechanical or electrical nature, which is explicitly identified by 
the bus chassis and/or body manufacturer in the owner's manual or factory service manual as 
requiring routine maintenance actions at intervals of one year or less. Tubing, wires and 
harnesses are considered to be serviceable components only at their attachments.  
 
 
FOR STUDYSASO STANDARD                                                           SASO/DS 31834/2020 
3 
  4- Technical requirements 
4.1 When each body panel joint, including small, curved, and complex joints, are tested in 
accordance with the test procedures described in item (5) shall hold the body panel to the 
member to which it is joined when subjected to a force of 60 % of the tensile strength of the 
weakest joined body panel determined according to 5.2, except the following requirements: 
(a) Any interior maintenance access panel or joint which lies forward of the passenger 
compartment. 
(b) Any interior maintenance access panel within the passenger compartment that does not 
exceed 305 mm when measured across any two points diametrically on opposite sides of the 
opening. 
(c) Trim and decorative parts which do not contribute to the strength of the joint, support 
members such as rub rails which are entirely outside of body panels, doors and windows, 
ventilation panels, and engine access covers. 
4.1.1 Body panels attached to each other shall have no unattached segment at the joint longer 
than 203 mm. 
 
5- Test procedures  
5.1 Preparation of the test specimen 
5.1.1 If a body panel joint is 203 mm or longer, cut a test specimen that consists of any 203 mm 
segment of the joint, together with a portion of the bus body whose dimensions are those 
specified in Figure (1), so that the specimen's centerline is perpendicular to the joint at the 
midpoint of the joint segment.  
Where the body panel joint is not fastened continuously, select the segment so that it does not 
bisect a spot weld or a discrete fastener.  
Support members which contribute to the strength of a body panel joint, such as rub rails on the 
outside of body panels or underlying structure attached to joint members, shall remain attached 
to the test specimen, except that material may be removed from the support members as 
necessary to clear the gripping areas of the joint members being tested. 
5.1.2 If a joint is less than 203 mm long, cut a test specimen with enough of the adjacent material 
to permit it to be held in the tension testing machine specified in item 5.3. 
5.1.3 Prepare the test specimen in accordance with the preparation procedures specified in 
ASTM E8/E8M. 
 
5.2 Determination of minimum allowable strength 
For purposes of determining the minimum allowable joint strength, determine the tensile 
strengths of the joined body components as follows: 
(a) If the mechanical properties of a joint component material are specified in ASTM E8/E8M, 
the lowest value of that material's thickness and tensile strength per unit of area shown in that 
source shall be used. 
(b) If the mechanical properties of a material are not specified in ASTM E8/E8M, determine its 
tensile strength by cutting a sheet specimen from outside the joint region of the bus body in 
accordance with Figure (1) of ASTM E8/E8M, and by testing it in accordance with 5.3. 
FOR STUDYSASO STANDARD                                                           SASO/DS 31834/2020 
4 
  (c) The cross-sectional area of material removed to facilitate the installation of fasteners shall 
be subtracted from the cross-sectional area of the panel in the determination of the tensile 
strength of the weakest joined body panel. 
 
5.3 Strength Test  
5.3.1 The joint specimen is gripped on opposite sides of the joint in a tension testing machine 
in accordance with ASTM E8/E8M. 
5.3.2 Adjust the testing machine grips so that the applied force on the joint is at 90 degrees plus 
or minus 3 degrees from the joint centerline, as shown in Figure (1). 
5.3.3 A tensile force is applied to the specimen by separating the heads of the testing machine 
at any uniform rate not less than 3 mm and not more than 10 mm per minute until the specimen 
separates. 
 
All dimensions in millimeters 
 
 
 
Figure (1) - Dimensions of the test specimen 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
FOR STUDYSASO STANDARD                                                           SASO/DS 31834/2020 
5 
  Bibliography  
 
 
[1] 49 Subtitle B-Chapter V-Part 571-Subpart B Section 221 
(FMVSS 571.221)  “School bus body joint strength.”. 
 
 
FOR STUDY